1. Field of the Invention
The present invention relates to an optical scanning apparatus, and in particular to an optical scanning apparatus with a spacing element.
2. Description of the Related Art
In an optical scanning device (scanner), target media is placed on a transparent glass platen to be scanned by an optical module disposed thereunder. The optical module usually includes a contact image sensor (CIS), moving backward and forward to scan the target media. Specifically, the transparent glass platen is separated from the optical module by a predetermined distance to guarantee a sufficient depth of field (focusing distance) therebetween. Thus, the optical module scans the target media and outputs a clear image corresponding thereto.
Referring to FIG. 1, a conventional optical scanning device 1 includes a transparent glass platen 11, an optical module 12 and a support structure 13. The support structure 13 supports the optical module 12, and the transparent glass platen 11 is disposed on the optical module 12. Additionally, multiple separators (or spacers) 14 are disposed on the optical module 12. The transparent glass platen 11 is supported by the separators 14 and is thereby separated from the optical module 12 by a predetermined distance. Moreover, the depth of field for the optical scanning device 1 is guaranteed by the separators 14. Nevertheless, disposing the separators 14 on the optical module 12 is complicated and inconvenient.
Another optical scanning device uses multiple separators (or spacers) disposed on the support structure thereof to guarantee the depth of field between the transparent glass platen and the optical module thereof. Similarly, disposing the separators (or spacers) on the support structure is complicated and inconvenient.